TWISTED GRAIN-BOUNDARY PHASE IN THE BINARY MIXTURE OF NEMATIC AND CHOLESTERYL COMPOUNDS

The binary mixture of cholesteryl nonanoate (CN) and 4,4'-hexyloxy azo xy benzene (HOB) exhibit a very interesting mesophases like blue phase , twisted drain boundary (TCB) phase, induced smectic A, smectic C and smectic B phases at different temperatures when the mixture is coo le d from isotropic phase. The existence of TGB phase is confirmed by DSC and optical microscopic studies. The mixtures with concentration 30 t o 45% of CN exhibit TGB phase at higher temperature. The optical aniso tropy of cholesteric phase is estimated. Numerous interesting optical textures are also illustrated.